diff options
| author | Benjamin Block <bblock@linux.ibm.com> | 2019-10-25 19:12:44 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-10-29 05:16:14 +0300 |
| commit | 7e418833e68948cb9ed15262889173b7db2960cb (patch) | |
| tree | 7a61e483bb7f76d6564a9fbfe6e18d6707af8133 /drivers/s390/scsi/zfcp_aux.c | |
| parent | 92953c6e0aa77d4febcca6dd691e8192910c8a28 (diff) | |
| download | linux-7e418833e68948cb9ed15262889173b7db2960cb.tar.xz | |
scsi: zfcp: diagnostics buffer caching and use for exchange port data
The FCP channel exposes two central interfaces to receive information about
the local FCP-Adapter/-Port: Exchange Port and Exchange Config Data. Using
these commands can negatively impact the adapter if we allow them to be
sent at a very high rate.
The later parts of this patchset will introduce new user-interfaces to
receive more diagnostics from the adapter. To prevent any negative impact
from using those, this patch adds a simple caching-mechanism that will
prevent a malicious/faulty userspace-application from generating an
abnormal high amount of Exchange Port/Config Data traffic.
Relevant diagnostic data that is received via Exchange Config/Port Data is
cached in buffers associated with the corresponding adapter-struct. Each
buffer is associated with a timestamp that signals how old the data is,
and, added via a following patch in this series, lets userspace-interfaces
determine when the data is too old and needs to be updated.
Buffer-updates are made during the normal response path of the
corresponding command. With this patch only the output of the Exchange Port
Data command is captured.
Link: https://lore.kernel.org/r/054ca020ce0a53dc0d9176428bea373898944e6a.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/s390/scsi/zfcp_aux.c')
| -rw-r--r-- | drivers/s390/scsi/zfcp_aux.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c index e390f8c6d5f3..a19189d7b3f3 100644 --- a/drivers/s390/scsi/zfcp_aux.c +++ b/drivers/s390/scsi/zfcp_aux.c @@ -4,7 +4,7 @@ * * Module interface and handling of zfcp data structures. * - * Copyright IBM Corp. 2002, 2017 + * Copyright IBM Corp. 2002, 2018 */ /* @@ -25,6 +25,7 @@ * Martin Petermann * Sven Schuetz * Steffen Maier + * Benjamin Block */ #define KMSG_COMPONENT "zfcp" @@ -36,6 +37,7 @@ #include "zfcp_ext.h" #include "zfcp_fc.h" #include "zfcp_reqlist.h" +#include "zfcp_diag.h" #define ZFCP_BUS_ID_SIZE 20 @@ -356,6 +358,9 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device) adapter->erp_action.adapter = adapter; + if (zfcp_diag_adapter_setup(adapter)) + goto failed; + if (zfcp_qdio_setup(adapter)) goto failed; @@ -449,6 +454,7 @@ void zfcp_adapter_release(struct kref *ref) dev_set_drvdata(&adapter->ccw_device->dev, NULL); zfcp_fc_gs_destroy(adapter); zfcp_free_low_mem_buffers(adapter); + zfcp_diag_adapter_free(adapter); kfree(adapter->req_list); kfree(adapter->fc_stats); kfree(adapter->stats_reset_data); |